Configuring SNMP

This chapter describes how to configure Simple Network Management Protocol (SNMP) to query the Cisco 4700 Series Application Control Engine (ACE) appliance for Cisco Management Information Bases (MIBs) and to send event notifications to a network management system (NMS).

Information About SNMP

SNMP is an application-layer protocol that facilitates the exchange of management information between an NMS, SNMP agents, and managed devices such as the ACE. You can configure the ACE to send traps (event notifications) to an NMS, or you can use the NMS to browse the MIBs that reside on the ACE.

The ACE contains an SNMP agent that provides support for network monitoring. The ACE supports SNMP Version 1 (SNMPv1), SNMP Version 2c (SNMPv2c), and SNMP Version 3 (SNMPv3).

SNMPv1 and SNMPv2c use a community string match for authentication. Community strings provide a weaker form of access control. SNMPv3 utilizes an SNMP user for authentication and provides improved access control by using strong authentication. SNMPv3 should be utilized instead of SNMPv1 and SNMPv2c wherever possible.

SNMPv3 is an interoperable standards-based protocol for network management. SNMPv3 provides secure access to devices by using a combination of authenticating and encrypting frames over the network. The SNMPv3 provides the following security features:

•Message integrity—Ensures that a packet has not been tampered with in-transit.

•Authentication—Determines that the message is from a valid source.

•Encryption—Scrambles the packet contents to prevent it from being seen by unauthorized sources.

Managers and Agents

•The manager monitors and controls all other SNMP-managed devices (network nodes) in the network. At least one SNMP manager must be in a managed network. The manager is installed on a workstation somewhere in the network.

•An agent resides in a managed device (a network node). An agent is a specialized software module that receives instructions from the SNMP manager and also sends management information back to the SNMP manager as events occur. For example, an agent might report such data as the number of bytes and packets in and out of the device or the number of broadcast messages sent and received.

There are many different SNMP management applications, but they all perform the same basic task. These applications allow SNMP managers to communicate with agents to monitor, configure, and receive alerts from the network devices.The ACE supports traps and SNMP get requests but does not support SNMP set requests to configure values on the device. You can use any SNMP-compatible NMS to monitor the ACE.

In SNMP, each variable is referred to as a managed object. A managed object is anything that an agent can access and report back to the NMS. All managed objects are contained in the MIB, which is a database of the managed objects called MIB objects. Each MIB object controls one specific function, such as counting how many bytes are transmitted through an agent's port. The MIB object consists of MIB variables, which define the MIB object name, description, and default value.The ACE maintains a database of values for each definition.

Browsing a MIB entails issuing an SNMP get request from the NMS. You can use any SNMPv3, MIB-II compliant browser to receive SNMP traps and browse MIBs.

SNMP Manager and Agent Communication

The SNMP manager and the agent can communicate in several ways. The Protocol Data Unit (PDU) is the message format that SNMP managers and agents use to send and receive information.

•The SNMP manager can perform the following operations:

–Retrieve a value (a get operation) from an agent. The SNMP manager requests information from the agent, such as the number of users logged on to the agent device, or the status of a critical process on that device. The agent gets the value of the requested MIB object and sends the value back to the manager (a get-response operation). The variable binding (varbind) is a list of MIB objects that allows a request recipient to see what the originator wants to know. Variable bindings are object identifiers (OID)=value pairs that make it easy for the NMS to identify the information that it needs when the recipient fills the request and sends back a response.

–Retrieve the value immediately after the variable that you name (a get-next operation). A get-next operation retrieves a group of values from a MIB by issuing a sequence of commands. By performing a get-next operation, you do not need to know the exact MIB object instance that you are looking for; the SNMP manager takes the variable that you name and then uses a sequential search to find the desired variables.

–Retrieve a number of values (a get-bulk operation). The get-bulk operation retrieves large blocks of data, such as multiple rows in a table, which would otherwise require the transmission of many small blocks of data.The SNMP manager performs a number of get-next operations that you specify.

•An agent can send an unsolicited message to the SNMP manager at any time if a significant, predetermined event takes place on the agent. This message is called an event notification. SNMP event notifications (traps or inform requests) are included in many MIBs and help to alleviate the need for the NMS to frequently poll (gather information through a get operation) the managed devices. For details on MIB objects and SNMP notifications supported by the ACE, see the "Supported MIBs and Notifications" section.

SNMP Traps and Informs

You can configure the ACE to send notifications (such as traps or inform requests) to SNMP managers when particular events occur. In some instances, traps can be unreliable because the receiver does not send any acknowledgment when it receives a trap and the sender cannot determine if the trap was received. However, an SNMP manager that receives inform requests acknowledges the message with an SNMP Response PDU. If the sender never receives a Response, the inform request is usually retransmitted. Inform requests are more likely to reach their intended destination.

Notifications may contain a list of MIB variable bindings that clarify the status being relayed by the notification. The list of variable bindings associated with a notification is included in the notification definition in the MIB. For standard MIBs, Cisco has enhanced some notifications with additional variable bindings that further clarify the cause of the notification.

Note The clogOriginID and clogOriginIDType variable bindings appended with each notification can be used by the NMS application to uniquely identify the device originating the trap. You can configure the values for clogOriginID and clogOriginIDType varbind to uniquely identify the device by using the logging device-id configuration mode command. For details on the logging device-id command, see the Cisco 4700 Series Application Control Engine Appliance System Message Guide.

Use the SNMP-TARGET-MIB to obtain more information on trap destinations and inform requests.

SNMPv3 CLI User Management and AAA Integration

The ACE implements RFC 3414 and RFC 3415, including the SMNPv3 User-based Security Model (USM) for message security and role-based access control. SNMP v3 user management can be centralized at the authentication and accounting (AAA) server level (as described in the Cisco 4700 Series Application Control Engine Appliance Security Configuration Guide). This centralized user management allows the ACE SNMP agent to use the user authentication service of an AAA server. After user authentication is verified, the SNMP protocol data units (PDUs) further processed. The AAA server is also used to store user group names. SNMP uses the group names to apply the user access and role policy that is locally available in the ACE.

CLI and SNMP User Synchronization

Any configuration changes to the user group, role, or password, results in the database synchronization for both SNMP and AAA.

Users are synchronized as follows:

•If you delete a user by using the nousername command, the user is also deleted from both SNMP and the CLI. However, if you delete a user by using the nosnmp-server user command, the user is deleted only from SNMP and not from the CLI.

•User-role mapping changes are synchronized in SNMP and the CLI.

Note When you specify a password in a localized key or encrypted format for security encryption, the password is not synchronized.

•The password specified in the username command is synchronized as the auth and priv passwords for the SNMP user.

•Existing SNMP users can continue to retain the auth and priv information without any changes.

•If you create a new user that is not present in the SNMP database by using the username command without a password, the SNMP user is created with the noAuthNoPriv security level.

For information about creating a CLI user by using the username command, see the Cisco 4700 Series Application Control Engine Appliance Virtualization Configuration Guide. To create an SNMP user by using the snmp-server user command, see the "Configuring SNMP Users" section.

Multiple String Index Guidelines

If any SNMP MIB table has more than one string index that contains more than 48 characters, the index may not show up in the MIB table when you perform an SNMP walk. According to SNMP standards, SNMP requests, responses, or traps cannot have more than 128 subidentifiers.

Note The maximum SNMP object identifier (OID) length supported by the ACE is 128 characters. If the SNMP OID exceeds this maximum, the ACE displays the error "Next OID length is greater than permissible."

The following list contains object names:

•Context name

•Real server name

•Server farm name

•Probe name

•HTTP header name

•ACL name

•Class map name

•Policy map name

•Resource class name

Table 7-1 identifies a list of tables that have more than one string index.

Table 7-1 SNMP MIB Tables with More Than One String Index

MIB Name

Table

String Indices

CISCO-ENHANCED- SLB-MIB.my

cesRserverProbeTable

cesRserverName,cesRserverProbeName

CISCO-ENHANCED-SLB-MIB.my

cesServerFarmRserverTable

slbServerFarmName, cesRserverName

CISCO-SLB-EXT-MIB.my

cslbxServerFarmProbeFarmName

cslbxServerFarmProbeFarmName,cslbxServerFarmProbeTableName

CISCO-SLB-HEALTH-MON-MIB.my

cshMonServerfarmRealProbeStatsTable

cslbxProbeName,slbServerFarmName,cshMonServerfarmRealServerName

Supported MIBs and Notifications

Note The maximum SNMP object identifier (OID) length supported by the ACE is 128 characters. If the SNMP OID exceeds this maximum, the ACE displays the error "Next OID length is greater than permissible."

Table 7-2 SNMP MIB Support

MIB Support

Capability MIB

Description

Appliance MIBs

CISCO-ENTITY-VENDORTYPE-OID-MIB

N/A

Defines the object identifiers (OIDs) assigned to various ACE components. The OIDs in this MIB are used by the entPhysicalTable of the ENTITY-MIB as values for the entPhysicalVendorType field in the entPhysicalTable. Each OID uniquely identifies a type of physical entity, such as a chassis, line cards, or port adapters. The entPhysicalVendorType OID values are listed as follows:

Provides basic management and identification of physical and logical entities within a network device. Software support for the ENTITY-MIB focuses on the physical entities within the ACE. This MIB provides details on each module, power supply, fan, and sensors within the ACE appliance chassis. It provides sufficient information to correctly map the containment of these entities within the ACE.

The ENTITY-MIB is supported only in the Admin context.

The ENTITY-MIB is described in RFC 4133.

ENTITY-SENSOR-MIB

CISCO-ENTITY-SENSOR-RFC-CAPABILITY

Contains a single group called the entitySensorValueGroup, which allows objects to convey the current value and status of a physical sensor. The entitySensorValueGroup contains a single table, called the entPhySensorTable, which provides a few read-only objects that identify the type of data units, scaling factor, precision, current value, and operational status of the sensor.

The ENTITY-SENSOR-MIB is supported only in the Admin context.

The ENTITY-SENSOR-MIB is described in RFC 3433.

SNMPv3 Agent MIBs

SNMP-COMMUNITY-MIB

CISCO-SNMP-COMMUNITY-CAPABILITY

Contains objects for mapping between community strings and version-independent SNMP message parameters. In addition, this MIB provides a mechanism for performing source address validation on incoming requests and for selecting community strings based on target addresses for outgoing notifications.

The SNMP-COMMUNITY-MIB is described in RFC 3584.

Note SNMP communities are applicable only for SNMPv1 and SNMPv2c. SNMPv3 requires user configuration information such as specifying the role group that the user belongs to, authentication parameters for the user, the authentication password, and message encryption parameters.

SNMP-FRAMEWORK-MIB

CISCO-SNMP-FRAMEWORK-CAPABILITY

Defines the elements of SNMP Management Frameworks, including an SNMP engine and Access Control Subsystem.

The SNMP-FRAMEWORK-MIB is described in RFC 3411.

SNMP-MPD-MIB

CISCO-SNMP-MPD-CAPABILITY.my

Describes the Message Processing Subsystem and Dispatcher for SNMP. The Dispatcher in the SNMP engine sends and receives SNMP messages. It also dispatches SNMP PDUs to SNMP applications. A Message Processing Model processes an SNMP version-specific message and coordinates the interaction with the Security Subsystem to ensure that proper security is applied to the SNMP message being handled.

The SNMP-MPD-MIB is described in RFC 3412.

SNMP-NOTIFICATION-MIB

CISCO-SNMP-NOTIFICATION-CAPABILITY

Defines MIB objects used by an SNMP entity for the generation of notifications.

The SNMP-NOTIFICATION-MIB is described in RFC 3413.

SNMP-TARGET-MIB

CISCO-SNMP-TARGET-CAPABILITY

Contains a table for the destination information and SNMP parameters in the management target message. There can be a many-to-many relationship in the MIB between these two types of information. Multiple transport end points may be associated with a particular set of SNMP parameters, or a particular transport end point may be associated with several sets of SNMP parameters.

The USM module decrypts incoming messages. The module then verifies the authentication data and creates the PDUs. For outgoing messages, the USM module encrypts PDUs and generates the authentication data. The module then passes the PDUs to the message processor, which then invokes the dispatcher.

The USM module's implementation of the SNMP-USER-BASED-SM-MIB enables the SNMP manager to issue commands to manage users and security keys. The MIB also enables the agent to ensure that a requesting user exists and has the proper authentication information. When authentication is done, the request is carried out by the agent.

The SNMP-USER-BASED-SM-MIB is described in RFC 3414.

Note User configuration is applicable only for SNMPv3; SNMPv1 and SNMPv2c use a community string match for user authentication.

The SNMP-VIEW-BASED-ACM-MIB specifies objects that are needed to control access to all MIB data that is accessible through the SNMP agent. Upon initialization, the VACM registers as the access control module with the agent infrastructure. The VACM implements access control checks according to several parameters that are derived from the SNMP message.

The SNMP-VIEW-BASED-ACM-MIB is described in RFC 3415.

Other MIBs

CISCO-AAA-SERVER-EXT-MIB

CISCO-AAA-SERVER-EXT-CAPABILITY

Acts as an extension to CISCO-AAA-SERVER-MIB. It enhances the casConfigTable of the CISCO-AAA-SERVER-MIB to include other types of server addresses. The CISCO-AAA-SERVER-EXT-MIB manages the following configuration functions:

•Generic configurations as applied on the authentication and accounting module.

•Configuration settings (settings for all the AAA servers instrumented in one instance of this MIB).

•AAA server group configuration.

•Application-to-AAA function-to-server group mapping configuration.

CISCO-AAA-SERVER-MIB

CISCO-AAA-SERVER-CAPABILITY

Provides configuration information and statistics that reflect the state of an AAA server operation within the device and AAA communications with external servers. The CISCO-AAA-SERVER-MIB provides the following information:

•A table for configuring AAA servers.

•Identities of external AAA servers.

•Statistics for each AAA function.

•Status of servers that provide AAA functions.

A server is defined as a logical entity that provides any of the AAA functions. The ACE can use a Remote Access Dial-In User Service (RADIUS), Terminal Access Controller Access Control System Plus (TACACS+), or Lightweight Directory Access Protocol (v3) (LDAP) protocols for remote authentication and designation of access rights.

CISCO-APPLICATION ACCELERATION-MIB

CISCO-APPLICATION- ACCELERATION-CAPABILITY-MIB

Manages application acceleration system(s) in the ACE. This MIB includes instrumentation for providing the performance statistics and status of the condenser which is the core of the application acceleration system. A condenser is a software accelerator that applies several optimization techniques to accelerate Web application access.

CISCO-ENHANCED-SLB-MIB

CISCO-ENHANCED-SLB-CAPABILITY

Supports the following server load-balancing functions:

•A real server configuration with a real server that is identified by a name.

•The current state of the real server (for example, OPERATIONAL, OUT-OF-SERVICE, PROBE-FAILED).

The slbEntity Index used in the table is the slot number of the ACE. Because the slot numbers value is not applicable for the ACE appliance, the slbEntity Index will always have a value of 1.

The cesRServerProbeTable table in the CISCO-ENHANCED-SLB-MIB provides details about the real server probe statistics available in the show probe detail command output.

The cesServerFarmRserverTable and cesRserverTable tables in the CISCO-ENHANCED-SLB-MIB provide details about the data available in the show rserver command output.

CISCO-IF-EXTENSION-MIB

CISCO-IF-EXTENSION-CAPABILITY

Provides a table that returns ifName to ifIndex mapping to assign the ifIndex to interfaces.

The CISCO-IF-EXTENSION-MIB is described in RFC 2863.

Note The Ethernet data port, Ethernet management port, and port-channel interfaces are available only in Admin context. In this case, the CISCO-IF-EXTENSION-MIB supports all the interfaces for Admin contexts, while each individual user context supports only VLAN and BVI interfaces.

The cippfIpProfileTable allows users to create, delete, and get information about filter profiles. Filter profiles are uniquely identified by the profile names. Filter profiles can be either simple or extended usage types. The cippfIfIpProfileTable applies the filtering profiles to device interfaces that run IP. A filter profile can be applied to multiple interfaces.

The cippfIpFilterTable contains ordered lists of IP filters for all filtering profiles. Filters and profiles are related if they have the same filter profile name. Filters of the same profile name belong to a common profile.

The cippfIpFilterHits provides the total number of hit counts for an access control entry.

The IP protocol is described in RFC 791.

CISCO-L4L7MODULE-REDUNDANCY-MIB

CISCO-L4L7MODULE-REDUNDANCY-CAPABILITY

Provides configuration information and statistic tables that reflect the redundancy (or fault tolerance) between an active and a standby ACE appliances. Each peer appliance can contain one or more fault-tolerant (FT) groups.

The CISCO-L4L7MODULE-REDUNDANCY-MIB provides redundancy information such as: FT state, IP address, peer FT state, peer IP address, software compatibility, license compatibility, number of groups to which a peer belongs, and the number of heartbeat messages transmitted and received.

The CISCO-L4L7MODULE-REDUNDANCY-MIB provides details about the fault tolerance statistics available in the show ft peer, show ft group detail, and show ft stats command output.

CISCO-L4L7RESOURCE-LIMIT-MIB

CISCO-L4L7MODULE-RESOURCE-LIMIT-CAPABILITY

Manages resource classes. The resources referenced in this MIB are in addition to the resource information that is available in other MIBs. This MIB applies to Layer 4 through 7 modules that support managing resource limits using a centralized approach.

The ciscoL4L7ResourceLimitTable, ciscoL4L7ResourceRateLimitTable, and ciscoL4L7ResourceUsageSummaryTable in the CISCO-L4L7RESOURCE-LIMIT-MIB provide details about the Current, Peak, and Denied statistics available in the show resource usage command output.

CISCO-MODULE-VIRTUALIZATION-MIB

CISCO-MODULE-VIRTUALIZATION-CAPABILITY

Provides a way to create and manage ACE user contexts (also referred as virtual contexts). A virtual context is a logical partition of a physical device (the ACE). A virtual context provides different service types that can be managed independently. Each virtual context is an independent entity with its own configuration. A user-created context supports most of the options that you can configure in the Admin context (the default ACE context). Each context can have a separate management IP address that allows a user to establish a remote connection to the ACE by using the Secure Shell (SSH) or Telnet protocols and to send other requests (such as SNMP or FTP).

This MIB contains tables that allow you to create or delete virtual contexts and assigning interfaces and interface ranges to virtual contexts.

CISCO-PROCESS-MIB

CISCO-PROCESS-CAPABILITY

Displays memory and process CPU utilization on Cisco devices. This information should be used only as an estimate. The value of cpmCPUTotalPhysicalIndex will always be 1.

The displayed system processes information at the CPU system level (the total CPU usage) and not on a per-context level.

CISCO-PRODUCTS-MIB

N/A

Contains the OIDs that can be reported in the sysObjectID object in the SNMPv2-MIB. The sysObjectID OID value is listed as follows:

The slbVServerInfoTable table in the CISCO-SLB-MIB provides details about the data available in the show service-policy command output.

The slbEntity Index used in the table is the slot number of the ACE. Because the slot numbers value is not applicable for the ACE appliance, the slbEntity Index will always have a value of one.

The following MIB objects for the ACE include non-SLB-related connections as well:

•slbStatsCreatedConnections

•slbStatsCreatedHCConnections

•slbStatsEstablishedConnections

•slbStatsEstablishedHCConnetions

•slbStatsDestroyedConnections

•slbStatsDestroyedHCConnections

•slbStatsReassignedConnections

CISCO-SLB-EXT-MIB

CISCO-SLB-EXT-CAPABILITY

Acts as an extension to the Cisco server load-balancing MIB (CISCO-SLB-MIB). It provides tables for the sticky configuration.

The cslbxServerFarmStatsTable table in the CISCO-SLB-EXT-MIB provides details about the data available in the show serverfarm command output.

The following MIB objects for the ACE include non-SLB-related connections as well:

•cslbxStatsCurrConnections

•cslbxStatsTimedOutConnections

The server farm can change from the inactive to active state or active to inactive state. The reasons for changing from the active to inactive state are as follows:

•All the real servers are down.

•All real servers in a single server farm are out of service because the real server(s) reach the maximum connection or maximum load state, or have a probe failure or an ARP failure.

•The server farm reaches its partial limits.

CISCO-SLB-HEALTH-MON-MIB

CISCO-SLB-HEALTH-MON-CAPABILITY

Acts as an extension to the Cisco server load-balancing MIB (CISCO-SLB-MIB). It provides tables for the health probe configuration and statistics of the ACE.

The cshMonSfarmRealProbeStatsTable and cslbxProbeCfgTable tables in the CISCO-SLB-HEALTH-MON-MIB provide details about the probe data available in the show probe detail command output.

CISCO-SSL-PROXY-MIB

CISCO-SSL-PROXY-CAPABILITY

Manages a Secure Socket Layer (SSL) Proxy device which terminates and accelerates SSL and Transport Layer Security (TLS) transactions. The proxy device can act as a SSL server or a SSL client depending on the configuration and the application.

This MIB is used for monitoring the statistics of the proxy services and the protocols including TCP, SSL, and TLS.

CISCO-SYSLOG-EXT-MIB

CISCO-SYSLOG-EXT-CAPABILITY

Extends the CISCO-SLB-MIB, provides additional server farm configuration parameters (cslbxServerFarmTable), and configures and monitors system log (syslog) management parameters for the ACE. Use this MIB to set up syslog servers and set logging severity levels.

Syslog is described by RFC 3164.

CISCO-SYSLOG-MIB

CISCO-SYSLOG-CAPABILITY

Describes and stores the system messages (syslog messages) generated by the ACE. The CISCO-SYSLOG-MIB provides access to the syslog messages through SNMP. The MIB also contains a history of syslog messages and objects to enable or disable the transmission of syslog notifications.

Note This MIB does not track messages that are generated from debug commands entered through the CLI.

Syslog is described by RFC 3164.

IF-MIB

CISCO-IF-CAPABILITY

Reports generic information on interfaces (for example, VLANs).

The IF-MIB is described in RFC 2863.

Note The Ethernet data port, Ethernet management port, and port-channel interfaces are available only in Admin context. In this case, the IF-MIB supports all the interfaces for Admin contexts, while each individual user context supports only VLAN and BVI interfaces.

IP-MIB

CISCO-IP-CAPABILITY

Defines managed objects for managing implementations of the IP and its associated Internet Control Message Protocol (ICMP), but excludes their management of IP routes.

The IP-MIB is described in RFC 4293.

SNMPv2-MIB

CISCO-SNMPv2-CAPABILITY

Provides the Management Information Base for SNMPv2. The management protocol, SNMPv2, provides for the exchange of messages that convey management information between the agents and the management stations.

The SNMPv2-MIB is described in RFC 3418.

TCP-MIB

CISCO-TCP-STD-CAPABILITY

Defines managed objects for managing the implementation of the Transmission Control Protocol (TCP).

Note The clogOrigin ID and clogOriginIDType variable bindings are appended to each notification listed in Table 7-4 to identify from which chassis, slot, and context combination that the event trap has originated.

Table 7-4 SNMP Trap Support

Notification Name

Location of the Notification

Description

authenticationFailure

SNMPv2-MIB

SNMP request fails because the NMS did not authenticate with the correct community string.

cesRealServerStateUpRev1

CISCO-ENHANCED-SLB-MIB

State of a real server configured in a server farm is up due to user intervention.The notification is sent with the following varbinds:

•cesRealServerName

•cesServerFarmRserverBackupPort

•cesServerFarmName

•cesServerFarmRserverAdminStatus

•cesServerFarmRserverOperStatus

•cesRserverIpAddressType

•cesRserverIpAddress

•cesServerFarmRserverDescr

cesRealServerStateDownRev1

CISCO-ENHANCED-SLB-MIB

State of a real server configured in a server farm is down due to user intervention. The notification is sent with the following varbinds:

•cesRealServerName

•cesServerFarmRserverBackupPort

•cesServerFarmName

•cesServerFarmRserverAdminStatus

•cesServerFarmRserverOperStatus

•cesServerFarmRserverStateDescr

•cesRserverIpAddressType

•cesRserverIpAddress

•cesServerFarmRserverDescr

cesRealServerStateChangeRev1

CISCO-ENHANCED-SLB-MIB

State of a real server configured in a server farm changed to a new state as a result of something other than a user intervention. This notification is sent for situations such as ARP failures, probe failures, and so on. The notification is sent with the following varbinds:

•cesRealServerName

•cesServerFarmRserverBackupPort

•cesServerFarmName

•cesServerFarmRserverAdminStatus

•cesServerFarmRserverOperStatus

•cesServerFarmRserverStateDescr

•cesRserverIpAddressType

•cesRserverIpAddress

•cesProbeName

•cesServerFarmRserverDescr

cesRserverStateUp

CISCO-ENHANCED-SLB-MIB

State of a global real server is up due to user intervention.

Note No separate cesRealServerStateUpRev1 notifications are sent for each real server that listens on this rserver.

cesRserverStateDown

CISCO-ENHANCED-SLB-MIB

State of a global real server is down due to user intervention.

Note No separatecesRealServerStateDownRev1 notifications are sent for each real server that listens on this rserver.

cesRserverStateChange

CISCO-ENHANCED-SLB-MIB

State of a global real server changed to a new state as a result of something other than a user intervention. This notification is sent for situations such as ARP failures, probe failures, and so on.

Note No separate cesRealServerStateChangeRev1 notifications are sent for each real server that listens on this rserver.

ciscoSlbVServerVIPStateChange

CISCO-SLB-MIB.my

State of Vserver changes. This notification is sent with the following var-binds:

•slbVServerState

•slbVServerStateChangeDescr

•slbVServerClassMap

•slbVServerPolicyMap

•slbVServerIpAddressType

•slbVServerIpAddress

•slbVServerProtocol

The change in the Vserver state could be due to different reasons, such as binding to the interface, removing an active server farm from the policy, and associating the virtual IP address (VIP) with a class map.

The ciscoSlbVServerVIPStateChange is specified in the CISCO-SLB-MIB.

ciscoSlbVServerStateChange

CISCO-SLB-MIB.my

Notification that a virtual IP address (VIP) is removed from a class map. This notification is also sent when the state of a virtual server has changed. The notification is sent with the following var-binds: slbVServerState

•slbVServerStateChangeDescr

•slbVServerClassMap

•slbVServerPolicyMap

The ciscoSlbVServerVIPStateChange notification will be sent when the configuration or association of the VIP address changes.

The ciscoSlbVServerStateChange is specified in the CISCO-SLB-MIB.

clogMessageGenerated

CISCO-SYSLOG-MIB

ACE generated one or more syslog messages.

clmLicenseExpiryNotify

CISCO-LICENSE-MGR-MIB

Notification that an installed feature license expires.

clmLicenseFileMissingNotify

CISCO-LICENSE-MGR-MIB

Notification that the system detects that one or more installed license files are missing.

clmLicenseExpiryWarningNotify

CISCO-LICENSE-MGR-MIB

Notification that the system detects an installed feature license is about to expire.

clmNoLicenseForFeatureNotify

CISCO-LICENSE-MGR-MIB

Notification that the system detects that no license is installed for a specific feature.

cmVirtContextAdded, cmVirtContextRemoved

CISCO-MODULE-VIRTUALIZATION-MIB

Notification that you created or deleted an ACE user context, also referred as a virtual context.

cslbxServerFarmStateChange

CISCO-SLB-EXT-MIB

Notification that all real servers in a server farm are down and the server farm has changed state. The varbind contains the following details:

•cslbxServerFarmName

•cslbxServerFarmState

•cslbxServerFarmStateChangeDescr

•cslbxServerFarmNumOfTimeFailOvers

•cslbxServerFarmNumOfTimeBkInServs

coldStart

SNMPv2-MIB

SNMP agent started after a cold restart (full power cycle) of the ACE.

linkUp, linkDown

SNMPv2-MIB

VLAN interface is up or down. A VLAN interface can be down, for example, if you specified the shut command followed by the no shut command, or the VLAN was removed from the switch configuration.

Note The Ethernet data port, Ethernet management port, and port-channel interfaces are available only in Admin context. In this case, the linkUp and link Down notifications support all the interfaces for Admin contexts, while each individual user context supports only VLAN and BVI interfaces.

Task Flow for Configuring SNMP

Step 1 If you are operating in multiple contexts, observe the CLI prompt to verify that you are operating in the desired context. If necessary, log directly in to, or change to, the correct context.

host1/Admin# changeto C1

host1/C1#

The rest of the examples in this procedure use the Admin context, unless otherwise specified. For details on creating contexts, see the Cisco 4700 Series Application Control Engine Appliance Virtualization Configuration Guide.

Step 11 Attach the traffic policy to a single VLAN interface or globally to all VLAN interfaces in the same context. For example, to specify an interface VLAN and apply the SNMP management policy map to the VLAN, enter:

host1/Admin(config)# interface vlan 50

host1/Admin(config-if)# ip address 172.16.10.0 255.255.255.254

host1/Admin(config-if)# service-policy input SNMP-ALLOW_POLICY

host1/Admin(config-if)# exit

Step 12 (Optional) Save your configuration changes to Flash memory.

host1/Admin(config)# exit

host1/Admin# copy running-config startup-config

Configuring SNMP Users

This section describes how to configure SNMP users from the ACE CLI. User configuration includes information such as specifying the role group that the user belongs to, authentication parameters for the user, the authentication password, and message encryption parameters.

The ACE synchronizes the interactions between the user created by the username command and by the snmp-server user command; updates to a user through the ACE CLI are automatically reflected in the SNMP server. For example, deleting a user automatically results in the user being deleted for both SNMP and CLI. In addition, user-role mapping changes are reflected in SNMP.

Caution If you change the SNMP engine ID for an Admin or user context, all configured SNMP users become invalid. You must recreate all SNMP users by using the
snmp-server user command in configuration mode. For more information on the SNMPv3 engine ID, see the
"Configuring an SNMPv3 Engine ID for an ACE Context" section.

Restrictions

This topic includes the following restrictions:

•The ACE supports a maximum of 28 SNMP users for each context.

•User configuration through the snmp-server user command is applicable for SNMPv3 only; SNMPv1 and SNMPv2c use a community string match for user authentication (see the "Defining SNMP Communities" section).

•user_name—Username. Enter an unquoted text string with no space and a maximum of 24 alphanumeric characters.

•group_name—(Optional) User role group to which the user belongs. Enter Network-Monitor, the default group name and the only role that is supported.

Note Only network monitoring operations are supported through the ACE implementation of SNMP. In this case, all SNMP users are automatically assigned the system-defined default group of Network-Monitor. For details on creating users, see the Cisco 4700 Series Application Control Engine Appliance Virtualization Configuration Guide.

•auth—(Optional) Sets authentication parameters for the user. Authentication determines that the message is from a valid source.

•password1—User authentication password. Enter an unquoted text string with no space and a maximum of 130 alphanumeric characters. The ACE automatically synchronizes the SNMP authentication password as the password for the CLI user. The ACE supports the following special characters in a password:

, . / = + - ^ @ ! % ~ # $ * ( )

Note that the ACE encrypts clear text passwords in the running-config.

•localizedkey—(Optional) Specifies that the password is in a localized key format for security encryption.

•priv—(Optional) Specifies encryption parameters for the user. The priv option and the aes-128 option indicate that this privacy password is for generating 128-bit AES key.

•aes-128—Specifies the 128-byte Advanced Encryption Standard (AES) algorithm for privacy. AES is a symmetric cipher algorithm and is one of the privacy protocols for SNMP message encryption. It conforms with RFC 3826.

Note For an SNMPv3 operation using the external AAA server, user configurations on this server require AES for SNMP PDU encryption.

•password2—Encryption password for the user. The AES priv password can have a minimum of eight characters. If the passphrases are specified in clear text, you can specify a maximum of 64 alphanumeric characters. If you use the localized key, you can specify a maximum of 130 alphanumeric characters. Spaces are not allowed. The ACE supports the following special characters in a password:

, . / = + - ^ @ ! % ~ # $ * ( )

Note that the ACE encrypts clear text passwords in the running-config.

Defining SNMP Communities

This section describes how to create or modify SNMP community names and access privileges. Each SNMP device or member is part of a community. An SNMP community determines the access rights for each SNMP device. SNMP uses communities to establish trust between managers and agents.

You supply a name to the community. After that, all SNMP devices assigned to that community as members have the same access rights (as described in RFC 2576). The ACE allows read-only access to the MIB tree for devices included in this community. The read-only community string allows a user to read data values, but prevents that user from modifying modify the data.

Caution If you change the SNMP engine ID for an Admin or user context, all configured SNMP communities are deleted. You must recreate all SNMP communities by using the
snmp-server community command in configuration mode. For more information on the SNMPv3 engine ID, see the
"Configuring an SNMPv3 Engine ID for an ACE Context" section.

Restrictions

This topics contains the following restrictions:

•SNMP communities are applicable for SNMPv1 and SNMPv2c only. SNMPv3 requires user configuration information such as specifying the role group that the user belongs to, authentication parameters for the user, authentication password, and message encryption parameters (see the "Configuring SNMP Users" section).

•Only network monitoring operations are supported through the ACE implementation of SNMP. In this case, all SNMP users are automatically assigned the system-defined default group of Network-Monitor. For details on creating users, see the Cisco 4700 Series Application Control Engine Appliance Virtualization Configuration Guide.

Detailed Steps

Command

Purpose

Step 1

config

Example:

host1/Admin# config

host1/Admin(config)#

Enters global configuration mode.

Step 2

snmp-server communitycommunity_name [groupgroup_name]

Example:

host1/Admin(config)# snmp-server community
SNMP_Community1 group Network-Monitor

Creates or modifies SNMP community names and access privileges.

The keywords, arguments, and options are as follows:

•community_name—SNMP community name for this system. Enter an unquoted text string with no space and a maximum of 32 alphanumeric characters.

•group group_name—(Optional) Identifies the role group to which the user belongs. Enter Network-Monitor, the default group name and the only role that is supported.

Note Only network monitoring operations are supported through the ACE implementation of SNMP. In this case, all SNMP users are automatically assigned the system-defined default group of Network-Monitor. For details on creating users, see the Cisco 4700 Series Application Control Engine Appliance Virtualization Configuration Guide.

no snmp-server communitycommunity_name [groupgroup_name | ro]

Example:

host1/Admin(config)# no snmp-server
community SNMP_Community1 group
Network-Monitor

(Optional) Removes an SNMP community.

Step 3

do copy running-config startup-config

Example:

host1/Admin(config)# do copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Configuring an SNMP Contact

This section describes how to specify the contact information for the SNMP system.

Restrictions

You can specify information for one contact name only.

Detailed Steps

Command

Purpose

Step 1

config

Example:

host1/Admin# config

host1/Admin(config)#

Enters global configuration mode.

Step 2

snmp-server contactcontact_information

Example:

host1/Admin(config)# snmp-server contact
"User1 user1@cisco.com"

Specifies the contact information for the SNMP system.

Enter the contact_information argument as a text string with a maximum of 240 alphanumeric characters, including spaces. If the string contains more than one word, enclose the string in quotation marks (" "). You can include information on how to contact the person; for example, you can provide a phone number or an e-mail address.

no snmp-server contact

Example:

host1/Admin(config)# snmp-server contact

(Optional) Removes the SNMP contact name.

Step 3

do copy running-config startup-config

Example:

host1/Admin(config)# do copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Configuring an SNMP Location

This section describes how to specify the SNMP system location.

Restrictions

You can specify one location only.

Detailed Steps

Command

Purpose

Step 1

config

Example:

host1/Admin# config

host1/Admin(config)#

Enters global configuration mode.

Step 2

snmp-server location location

Example:

host1/Admin(config)# snmp-server location
"Boxborough MA"

Specifies the SNMP system location.

Enter the location argument as the physical location of the system. Enter a text string with a maximum of 240 alphanumeric characters, including spaces. If the string contains more than one word, enclose the string in quotation marks (" ").

no snmp-server location

Example:

host1/Admin(config)# no snmp-server
location

Removes the SNMP system location information.

Step 3

do copy running-config startup-config

Example:

host1/Admin(config)# do copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Configuring SNMP Notifications

This section describes how to configure the ACE to send traps or inform requests as notifications to an SNMP manager when a particular event occurs. In some instances, traps are unreliable because the receiver does not send any acknowledgment when it receives a trap. The sender cannot determine if the trap was received. However, an SNMP manager that receives inform requests acknowledges the message with an SNMP Response PDU. If the sender never receives a Response, the inform request is normally retransmitted. Inform requests are more likely to reach their intended destination.

Use the SNMP-TARGET-MIB to obtain more information on the destinations to which notifications are to be sent either as traps or as SNMP inform requests. See the "Supported MIBs and Notifications" section for details.

•informs—(Optional) Sends SNMP inform requests to the identified host, which allows for manager-to-manager communication. Inform requests can be useful when the need arises for more than one NMS in the network.

•traps—(Optional) Sends SNMP traps to the identified host. A trap is the method for an agent to tell the NMS that a problem has occurred. The trap originates from the agent and is sent to the trap destination, as configured within the agent itself. Typically the trap destination is the IP address of the NMS.

•version 1 | 2c | 3—(Optional) Specifies the version of SNMP used to send the traps. SNMPv3 is the most secure model because it allows packet encryption with the priv keyword. To specify a version, enter one of the following:

–1—Specifies SNMPv1. This option is not available for use with SNMP inform requests.

(Optional) Copies the running configuration to the startup configuration.

Enabling SNMP Notifications

This section describes how to enable the ACE to send SNMP notification traps and inform requests to the NMS. Notification traps and inform requests are system alerts that the ACE generates when certain events occur. SNMP notifications can be sent to the NMS as traps or inform requests. By default, no SNMP notification is defined or issued.

Restrictions

This topic includes the following restrictions:

•To configure the ACE to send the SNMP notifications, specify at least one snmp-server enable traps command. To enable multiple types of notifications, you must enter a separate snmp-server enable traps command for each notification type and notification option. If you enter the command without any keywords, the ACE enables all notification types and traps.

•The notification types used in the snmp-server enable traps command all have an associated MIB object that globally enables or disables them. However, not all of the notification types available in the snmp-server host command have notificationEnable MIB objects, so some of the notification types cannot be controlled by using the snmp-server enable command.

Prerequisites

The snmp-server enable traps command is used with the snmp-server host command (see the "Configuring SNMP Notification Hosts" section). The snmp-server host command specifies which host receives the SNMP notifications. To send notifications, you must configure at least one SNMP server host.

Detailed Steps

Command

Purpose

Step 1

config

Example:

host1/Admin# config

host1/Admin(config)#

Enters global configuration mode.

Step 2

snmp-server enable traps [notification_type] [notification_option]

Example:

host1/Admin(config)# snmp-server enable
traps slb real

Enables the ACE to send SNMP traps and informs to the NMS.

The keywords, arguments, and options are as follows:

•notification_type—(Optional) Type of notification to enable. If no type is specified, the ACE sends all notifications. Specify one of the following keywords as the notification_type:

–license—Sends SNMP license manager notifications. This keyword appears only in the Admin context.

–slb—Sends server load-balancing notifications. When you specify the slb keyword, you can specify a notification_option value.

–snmp—Sends SNMP notifications. When you specify the snmp keyword, you can specify a notification_option value.

–syslog—Sends error message notifications (Cisco Syslog MIB).

Note To enable system messages to be sent as traps to the NMS, you can specify the logging history command. You specify the level of messages to be sent with the logging history level command. You must also enable syslog traps by using the snmp-server enable traps command. See the Cisco 4700 Series Application Control Engine Appliance System Message Guidefor details.

•notification_option—(Optional) Enables the following SNMP notifications:

–When you specify the snmp keyword, specify the authentication, coldstart, linkdown, or linkup keyword to enable SNMP notifications. This selection generates a notification if the community string provided in the SNMP request is incorrect, or when a VLAN interface is either up or down. The coldstart keyword appears only in the Admin context.

–When you specify the slb keyword, specify the real, serverfarm,or vserver keyword to enable server load-balancing notifications. This selection generates a notification if the following state change occurs:

The real server changes state (up or down) due to user intervention, ARP failures, or probe failures.

The server farm changes state because all real servers in the server farm are down.

The virtual server changes state (up or down). The virtual server represents the servers behind the content switch in the ACE to the outside world and consists of the following attributes: the destination address (can be a range of IP addresses), the protocol, the destination port, or the incoming VLAN.

no snmp-server enable traps [notification_type] [notification_option]

Example:

host1/Admin(config)# no snmp-server enable
traps slb real

Disables SNMP server notifications.

Step 3

do copy running-config startup-config

Example:

host1/Admin(config)# do copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Examples

The following example shows how to enable the ACE to send server load-balancing traps to the host at IP address 192.168.1.1 using a community string:

host1/Admin(config)# snmp-server host192.168.1.1

host1/Admin(config)# snmp-server community SNMP_Community1 group Network-Monitor

host1/Admin(config)# snmp-server enable traps slb real

Enabling the IETF Standard for SNMP linkUp and linkDown Traps

This section describes how to configure the ACE to send the Internet Engineering Task Force (IETF) standards-based implementation for linkUp and linkDown traps (as outlined in RFC 2863) rather than send the Cisco implementation of linkUp and linkDown traps to the NMS. By default, the ACE sends the Cisco implementation of linkUp and linkDown traps to the NMS. The ACE sends the Cisco Systems IF-MIB variable bindings, which consists of ifIndex, ifAdminStatus, ifOperStatus, ifName, ifType, clogOriginID, and clogOriginIDType.

Note The Cisco variable bindings are sent by default. To receive RFC 2863-compliant traps, you must specify the snmp-server trap link ietf command.

(Optional) Copies the running configuration to the startup configuration.

Assigning a Trap-Source Interface for SNMP Traps

This section describes how to specify the VLAN interface that is the trap source address contained in the SNMP v1 trap PDU.

Restrictions

This topic includes the following restrictions:

•If you do not configure the snmp-server trap-source command, the ACE takes the source IP address from the internal routing table, which is dependant on the destination host address where the notification is to be sent.

•If you specify a VLAN number of an interface that does not have a valid IP address, the ACE fails in sending notifications for SNMP v1 traps.

•The ACE restricts you from selecting the VLAN number of the FT VLAN interface that has been specified between redundant ACEs as the trap source address contained in the SNMP v1 trap PDU.

Detailed Steps

Command

Purpose

Step 1

config

Example:

host1/Admin# config

host1/Admin(config)#

Enters global configuration mode.

Step 2

snmp-server trap-source vlan number

Example:

host1/Admin(config)# snmp-server
trap-source vlan 50

Specifies the VLAN interface that is the trap source address contained in the SNMP v1 trap PDU.

The number argument specifies the number of the VLAN interface that is the trap source address contained in the SNMP v1 trap PDU.Enter a value from 2 to 4094 for an existing VLAN interface.

Note The ACE now restricts you from selecting the VLAN number of the FT VLAN interface that has been specified between redundant ACE appliances as the trap source address contained in the SNMP v1 trap PDU.

(Optional) Copies the running configuration to the startup configuration.

Accessing ACE User Context Data Through the Admin Context IP Address

This section describes how SNMP managers can send requests to a context by using the IP address to get the data that corresponds to the context.The ACE Admin context and each ACE user context has its own IP address. The SNMP agent supports a community string for SNMPv1 and SNMPv2 and a username for SNMPv3 on a per-context basis.

You can also retrieve data for user contexts by using the IP address for the Admin context. The Admin context credentials also allow access to user context data, such as performance and configuration information.

Restrictions

Notifications for user contexts cannot be sent through the Admin context.

Accessing User Context Data When Using SNMPv1/v2

This section describes how with SNMPv1/v2, you can access MIBs available for a user context through an Admin context IP address by specifying the appropriate SNMP version, the Admin context IP address, and the Admin context community string embedded with the name of the user context. The format for the community string is as follows:

admin_community_string@ACE_context_name

The ACE_context_name can be Admin or any ACE user context. If you do not specify a context name, the request is for the Admin context.

Examples

The following example shows how to return data for user context C1 when the Admin context has a configured community string of adminCommunity and an IP address of 10.6.252.63:

snmpget -v2c -c adminCommunity@C1 10.6.252.63 udpDatagrams.0

Accessing User Context Data When Using SNMPv3

This section describes how with SNMPv3, you can access MIBs for a user context through an Admin context IP address by using the Admin context IP address, the appropriate SNMP version, the Admin context username, and the user context name supported by the Admin context in the SNMPv3 packet. The ACE uses the user context name in the SNMPv3 context field of the request.

Note The SNMPv3 engine represents a logically separate SNMP agent. The ACE automatically creates an SNMP engine ID for each context or you can configure it. For more information on configuring an SNMPv3 engine ID, see the "Configuring an SNMPv3 Engine ID for an ACE Context" section.

Examples

The following example shows how to return data from user context C2 when the Admin context has a configured SNMP user snmpuser and an IP address of 10.6.252.63:

The ACE uses the user context C2 in place of the SNMPv3 context field in the request.

Note The SNMPv3 request is dropped if the request is sent to the IP address of the user context with a SNMPv3 context name field set to an empty string ("").

Configuring an SNMPv3 Engine ID for an ACE Context

This section describes how to configure an SNMP engine ID for the Admin or user context. By default, the ACE automatically creates an SNMP engine ID for the Admin context and each user context. The SNMP engine represents a logically separate SNMP agent. The IP address for an ACE context provides access to only one SNMP engine ID.

Caution If you change the SNMP engine ID for an Admin or user context, all configured SNMP users become invalid and all SNMP communities are deleted. You must recreate all SNMP users by using the
snmp-server user command in configuration mode, and recreate all SNMP communities by using the
snmp-server community command in configuration mode (see the
"Defining SNMP Communities" section).

(Optional) Copies the running configuration to the startup configuration.

Configuring SNMP Management Traffic Services

This section describes how to configure SNMP management traffic to and from the ACE through the use of class maps, policy maps, and service policies. The following items summarize the role of each function in configuring remote network management access to the ACE:

•Service policy—Activates the policy map, and attaches the traffic policy to a VLAN interface or globally on all VLAN interfaces.

This section provides an overview on creating a class map, policy map, and service policy for SNMP access.

SNMP remote access sessions are established to the ACE per context. For details on creating contexts and users, see the Cisco 4700 Series Application Control Engine Appliance Virtualization Configuration Guide.

Creating and Configuring a Layer 3 and Layer 4 Class Map

This section describes how to create a Layer 3 and Layer 4 class map to classify the SNMP management traffic that can be received by the ACE. This class map allows the ACE to receive the network management traffic by identifying the incoming IP protocols that the ACE can receive and the client source host IP address and subnet mask as the matching criteria. The class map also defines the allowed network traffic as a form of management security for protocols such as SNMP.

A class map can have multiple match commands. You can configure class maps to define multiple SNMP management protocol and source IP address commands in a group that you then associate with a traffic policy. The match-all and match-any keywords determine how the ACE evaluates multiple match statements operations when multiple match criteria exist in a class map.

Create a Layer 3 and Layer 4 class map to classify the SNMP management traffic that can be received by the ACE.

The keywords, arguments, and options are as follows:

•match-all | match-any—(Optional) Determines how the ACE evaluates Layer 3 and Layer 4 network traffic when multiple match criteria exist in a class map. The class map is considered a match if the match commands meet one of the following conditions:

–match-all —(Default) All of the match criteria listed in the class map match the network traffic class in the class map (typically, match commands of the same type).

–match-any—Only one of the match criteria listed in the class map matches the network traffic class in the class map (typically, match commands of different types).

•map_name—Name assigned to the class map. Enter an unquoted text string with no spaces and a maximum of 64 alphanumeric characters.

Configures the class map to specify that SNMP can be received by the ACE and an NMS. You configure the associated policy map to permit SNMP access to the ACE. As part of the network management access traffic classification, you also specify either a client source host IP address and subnet mask as the matching criteria or instruct the ACE to allow any client source address for the management traffic classification.

The keywords, arguments, and options are as follows:

•line_number—(Optional) Line number to identify individual match commands to help you edit or delete them. Enter an integer from 2 to 255. You can enter noline_number to delete long match commands instead of entering the entire line. The line numbers do not dictate a priority or sequence for the match statements.

•any—Specifies any client source address for the management traffic classification.

•source-address—Specifies a client source host IP address and subnet mask as the network traffic matching criteria. As part of the classification, the ACE implicitly obtains the destination IP address from the interface on which you apply the policy map.

Configures a Layer 3 and Layer 4 policy map that permits the ACE to receive the SNMP management protocol. The ACE executes the action for the first matching classification. The ACE does not execute any additional actions.

The map_name argument specifies the name assigned to the Layer 3 and Layer 4 network management policy map. Enter an unquoted text string with no spaces and a maximum of 64 alphanumeric characters.

Specifies a Layer 3 and Layer 4 traffic class created with the class-map command to associate network traffic with the traffic policy.

The arguments keywords, and options are as follows:

•name1—Name of a previously defined Layer 3 and Layer 4 traffic class, configured with the class-map command, to associate traffic to the traffic policy. Enter an unquoted text string with no spaces and a maximum of 64 alphanumeric characters.

•insert-beforename2—(Optional) Places the current class map ahead of an existing class map or inline match condition specified by the name2 argument in the policy map configuration. The ACE does not save the sequence reordering as part of the configuration. Enter an unquoted text string with no spaces and a maximum of 64 alphanumeric characters.

•class-default—Specifies the class-default class map for the Layer 3 and Layer 4 traffic policy. This class map is a reserved class map created by the ACE. You cannot delete or modify this class. All network traffic that fails to meet the other matching criteria in the named class map belongs to the default traffic class. If none of the specified classifications match, the ACE then matches the action specified under the classclass-default command. The class-default class map has an implicit match any statement in it and is used to match any traffic classification.

Restrictions

The ACE allows only one policy of a specific feature type to be activated on a given interface.

Detailed Steps

Command

Purpose

Step 1

config

Example:

host1/Admin# config

host1/Admin#(config)#

Enters global configuration mode.

Step 2

service-policy inputpolicy_name

Example:

host1/Admin(config)# service-policy input SNMP_MGMT_ALLOW_POLICY

Globally applies the SNMP management policy map to all of the VLANs associated with a context.

The keywords and arguments are as follows:

•input—Specifies that the traffic policy is to be attached to the input direction of an interface. The traffic policy evaluates all traffic received by that interface.

•policy_name—Name of a previously defined policy map, configured with a previously created policy-map command. The name can be a maximum of 40 alphanumeric characters.

If you are applying the policy map globally to all of the VLANs associated with a context

no service-policy inputpolicy_name

Example:

host1/Admin(config)# no service-policy input SNMP_MGMT_ALLOW_POLICY

(Optional) Removes the SNMP management policy map from all of the VLANs associated with a context.

When you remove a policy, the ACE automatically resets the associated service policy statistics to provide a new starting point for the service policy statistics the next time that you attach a traffic policy to a specific VLAN interface or globally to all VLAN interfaces in the same context.

Step 3

do copy running-config startup-config

Example:

host1/Admin(config)# do copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Applying a Service Policy to a Specific VLAN Interface

This section describes how to apply an existing policy map to a specific VLAN interface. A policy activated on an interface overwrites any specified global policies for overlapping classification and actions.

When you remove a policy, the ACE automatically resets the associated service policy statistics to provide a new starting point for the service policy statistics the next time that you attach a traffic policy to a specific VLAN interface or globally to all VLAN interfaces in the same context.

Step 5

do copy running-config startup-config

Example:

host1/Admin(config-if)# do copy running-config startup-config

(Optional) Copies the running configuration to the startup configuration.

Displaying or Clearing SNMP and Service Policy Statistics

This section describes how to display or clear SNMP and service policy statistics. It contains the following topics:

Displaying SNMP Statistical Information

To display SNMP statistics and configured SNMP information, use the following show commands:

Command

Purpose

show snmp [community | engineID | group | host | sessions | user]

Displays SNMP statistics and configured SNMP information. By default, this command displays the ACE contact, ACE location, packet traffic information, community strings, and user information. You can instruct the ACE to display specific SNMP information by including the appropriate keyword.

The keywords are as follows:

•community—(Optional) Displays SNMP community strings.

•engineID—(Optional) Displays the identification of the local SNMP engine and all remote engines that have been configured on the ACE.

•group—(Optional) Displays the names of groups on the ACE, the security model, the status of the different views, and the storage type of each group.

Name of the SNMP group or collection of users that have a common access policy

Security model

Security model used by the group, either v1, v2c, or v3

Security level

Security level used by the group

Read view

String that identifies the read view of the group

Write view

String that identifies the write view of the group

Notify view

String that identifies the notify view of the group

Storage-type

Status of whether the settings have been set in volatile or temporary memory on the device or in nonvolatile or persistent memory where settings will remain after the device has been turned off and on again

Row status

Indicates whether the Row status for the SNMP group is active or inactive

•policy_name—Identifier of an existing policy map that is currently in service (applied to an interface) as an unquoted text string with a maximum of 64 alphanumeric characters.

•detail—(Optional) Displays a more detailed listing of policy map statistics and status information.

Note The ACE updates the counters that the show service-policy command displays after the applicable connections are closed.

Examples

The following examples shows how to display service policy statistics for the SNMP_MGMT_ALLOW_POLICY policy map:

host1/Admin# show service-policy SNMP_MGMT_ALLOW_POLICY

Status : ACTIVE

Description: Allow mgmt protocols

-----------------------------------------

Context Global Policy:

service-policy: SNMP_MGMT_ALLOW_POLICY

Clearing SNMP Service Policy Statistics

To clear the statistical information of the service policies associated with your SNMP configuration, use the following clear command:

Command

Purpose

clear service-policypolicy_name

Clears the service policy statistics.

For the policy_name argument, enter the identifier of an existing policy map that is currently in service (applied to an interface).

Example of an SNMP Configuration

The following example illustrates a running-configuration that verifies the current status of a real server through SNMP and the CLI. It also verifies that SNMP traps are sent when a real server or virtual server is not operational. This example illustrates that you can restrict the client source host IP address allowed to connect to the ACE. The policy map is applied to all of the VLAN interfaces associated with the context. The SNMP configuration appears in bold in the example.